Cyclopentadiene, cyclopentene and cyclopentane and alkylated derivatives thereof are known in the art. Further, methods are known for preparation of alkylated cyclopentadienes and conversion of these materials to cyclopentenes and cyclopentanes. There is substantial interest in cyclopentadienes, cyclopentenes, and cyclopentanes since cyclopentadiene is characterized by the unique property of being the most acidic aliphatic hydrocarbon known, having a pKa of 18, and also because its reactions as a Diels-Alder diene are extremely facile. Because of the aromaticity of the cyclopentadiene anion (c--C.sub.5 H.sub.5.sup.-), cyclopentadiene is easily the most acidic of the simple hydrocarbons and in fact is comparable in acidity to alcohols. This means that substantial amounts of the anion can be generated with alkoxides and even concentrated solutions of hydroxide. Since it it uniquely stable, it can participate in the carbanion reactions of alkylation, acylation, carboxylation and the like.
U.S. Pat. No. 3,255,267 to Fritz et al relates to the alkylation of cyclopentadienes and discloses the reaction of 1-alkyl or 2-alkyl cyclopentadienes with a primary or secondary alcohol in the presence of an alkaline catalyst to alkylate in either the 1 to 2 position. The 1 isomer may then be further alkylated in either the 3 or 4 position while the 2 isomer can be further alkylated in the 4 position, all of this resulting in the formation of a mixture of isomers. Trialkylated and tetralkylated products are also disclosed. The compounds are described as being capable of epoxidation, polymerization, or for use as intermediates for preparation of other compounds. The alkyl groups added to the cyclopentadiene structure are inclusive of alkyl radicals having 1 to 11 carbon atoms in n-alkyl chains and up to 21 carbon atoms in side chains when the compounds are formed from secondary alcohols and including up to four alkyl substituents on the said cyclopentadiene.
U.S. Pat. No. 3,560,583 discloses cyclopentadiene compounds containing up to five substituents, which substituents can be independently hydrogen, alkyl, aryl or aralkyl. These compounds are prepared by reaction of a cyclopentadiene compound with benzyl halide or allyl halide, an alkali metal hydroxide and a quaternary ammonium salt catalyst.
Polish Pat. No. 55,535 to Makosza, 1968, discloses indene compounds which contain alkyl substituents on the cyclopentadiene portion of the molecule. However, the working examples indicate that only a single alkyl group or two allyl groups are present. U.S. Pat. No. 3,931,334 discloses lubricant compositions which comprise substituted indans, the indan molecule being substituted by methyl and styryl.
In a thesis by Stephen S. Hirsch, University of Maryland, 1963, there is disclosure of base catalyzed alkylation of cyclopentadienes utilizing alcohols to effect the alkylation. Included in this disclosure are alkylation reactions with benzyl alcohol to produce cyclopentadienes which can contain as many as five benzyl substituents. Also disclosed are 1,3-dialkyl indenes.
Polish Pat. No. 55,571 to Makosza discloses cyclopentadienes and processes for preparation of monosubstituted cyclopentadienes by the use of phase-transfer alkylation. The patent is limited to monosubstituted compounds with short chain alkyl groups.
The prior art contains numerous disclosures of methods for the preparation of substituted cyclopentadienes but wherein the substituents usually are short chain alkyl groups. The methods of preparation of such materials vary but do include such processes as the reaction of the cyclopentadiene with alkyl halides in the presence of a base as in U.S. Pat. No. 2,953,607. Similar disclosures may be found in U.S. Pat. Nos. 3,131,227, 4,547,603, 4,567,308, 3,560,583, 4,412,088, and 3,755,492. Of particular interest is 3,131,227 which discloses polysubstituted cyclopentadienes such as pentamethyl and hexamethyl cyclopentadiene which is prepared by a cyclization reaction. Also in Pat. No. 4,567,308, alkyl cyclopentadienes and alkylated derivatives thereof are prepared by the vapor phase reaction of a cyclopentadiene derivative and an aliphatic lower alcohol in the presence of a basic catalyst. These cyclopentadienes and alkylated products are disclosed as being additives for synthetic rubbers, starting materials for resins and/or industrial chemicals.
In a publication by J. Denis, Journal of Synthetic Lubrication, Vol. 1, p. 201-219 (1985), there is disclosure of hydrocarbons which may be used in lubricant compositions. Specifically mentioned in this publication are cycloalkanes and in particular monoalkyl substituted cyclopentanes. This publication is a comparison of various hydrocarbon structures including normal alkanes, alkanes branched by one or more alkyl chains or by a ring, cycloalkanes and aromatics as base stocks for lubricants.
In a publication by Rong et al, Acta Chemica Sinica, Vol. 41, No. 10, October, 1983, pages 971-973 there is disclosure of the use of polyethylene glycol as a phase transfer agent for halide alkylation of cyclopentadiene with alkyl halides. The products produced are monoalkyl substituted cyclopentadienes. In a related article by Rong et al, Journal of Chinese Universities, Vol. 4, page 576-580 (1983), there is disclosure of the synthesis of alkyl substituted derivatives of cyclopentadiene by the phase transfer catalytic reaction of cyclopentadiene with alkyl halides in the presence of potassium hydroxide and polyoxyethylene surfactants as a catalyst. Only monoalkyl substituted cyclopentadienes are prepared.
U.S. Pat. Nos. 3,004,384, 3,356,704, 3,358,008, 3,388,180, 3,391,209, 3,414,626, and 3,419,622 disclose polysubstituted cyclopentadienes and cyclopentanes but wherein the substituent is a short chain alkyl group group or allyl group. Finally, U.S. Pat. Nos. 3,751,500 and 3,636,176 disclose indene compounds which can contain short chain alkyl substituents which are useful as perfume compositions.
In none of the prior art of which Applicants are aware are there disclosures of poly-hydrocarbyl cyclopentanes, cyclopentadienes, cyclopentenes, and mixtures thereof which are useful as lubricant compositions, which useful products may be prepared from novel hydrocarbyl-substituted cyclopentadienes. The present invention provides such novel products as well as methods for their preparation and methods for their use.